1. Technical Field
The present disclosure relates to correction for distortions arising from use of a rolling shutter, and more particularly for use in a camera based driver assistance/control system.
2. Description of Related Art
Rolling shutter is a method of image acquisition in which each frame is recorded not from a snapshot of a single point in time, but rather by scanning across the image frame, for instance row by row. With a rolling shutter, not all parts of the image are recorded at exactly the same time, even though the whole frame may be displayed at the same time during playback. The rolling shutter is in contrast with a global shutter where the entire frame is exposed for the same time window.
Ego-motion “self-motion” refers to the translation and orientation (e.g. yaw, pitch and roll) in time of moving camera. A measure of ego-motion or of the camera mounted in a vehicle is important for driver assistance and/or vehicle control systems in order to accurately detect, recognize and avoid false positive detections of: other vehicles, obstacles, lights, street signs, lane markers and/or guard rails in the road environment.
Structure-from-Motion (SfM) refers to methods for recovering three-dimensional information of a scene that has been projected onto the focal plane(s) of a moving camera or multiple cameras. The structural information derived from a SfM algorithm may take the form of a set of projection matrices, one projection matrix per image frame, representing the relationship between a specific two-dimensional point in the image plane and its corresponding three-dimensional point. SfM algorithms rely on tracking specific image features from image frame to image frame to determine structural information concerning the scene.